The costs of electricity and water consumption are included in the service costs, so you already pay this with your rent. You also already pay for your heating costs.
Do you cook on gas? Then you will have to find a supplier yourself, you will also have to arrange this yourself for electricity.
Tip: ask your housemates! There is probably already a contract through one of your housemates.
The settlement of the service costs usually takes place before July 1 of the relevant year. For more information about your heating and service costs, click on the links below.